Castro Marim

A hill town above the Guadiana salt marshes with two castles, a medieval fair and a nature reserve rich in flamingos.

Castro Marim sits on a pair of hills above the flat marshlands of the lower Guadiana, roughly four kilometres north of the border crossing to Ayamonte in Spain. The town has a strategic importance that dates back to antiquity, and its two castles testify to centuries of frontier defence along the river that has divided Portugal and Spain since the Middle Ages.

The Castelo de Castro Marim, on the higher of the two hills, was built in the 13th century and served as the first headquarters of the Order of Christ, successor to the Knights Templar in Portugal. The castle was heavily damaged in the 1755 earthquake but retains its curtain walls, towers and keep. Inside the walls, the remains of a small church and cistern are visible, and the views across the marshes to Spain are commanding. An interpretive display inside the castle explains its role in the Reconquista and the history of the military orders that defended the Portuguese frontier.

On the adjacent hill, the 17th-century Forte de Sao Sebastiao was built during the Restoration War as an artillery fort to complement the medieval castle. The two fortifications together formed a formidable defensive position controlling the Guadiana crossing. The fort is now used as a venue for the annual Medieval Fair, held each August over four days, which draws tens of thousands of visitors for jousting, falconry, period markets, costumed parades and open-air banquets served on trestle tables. The fair is one of the largest historical re-enactment events in Portugal.

Below the castle hills, the Reserva Natural do Sapal de Castro Marim e Vila Real de Santo Antonio protects a large area of salt marsh, salt pans and tidal flats that form one of the most important wetland habitats in the Algarve. The reserve supports breeding populations of greater flamingos, avocets, black-winged stilts and several species of tern. A network of trails and hides allows birdwatchers to explore the marshes, and flamingos can often be seen from the main road, their pink forms vivid against the white salt pans.

The town itself has a small but pleasant centre with a handful of restaurants, cafes and shops. Castro Marim is known for its flor de sal, artisanal sea salt harvested from the traditional salt pans in the marshes below the town. The salt is prized by Portuguese chefs and is sold in local shops and at the weekly market. The salt pans themselves are an ancient feature of the landscape, and some have been in continuous use for centuries. A visitor centre near the pans explains the harvesting process.

Castro Marim is well connected by road, sitting just off the A22 motorway and the EN125. The Spanish city of Ayamonte is a short drive across the Guadiana bridge, and Vila Real de Santo Antonio is four kilometres to the south. The town makes a practical base for exploring the eastern Algarve border region, and the combination of castles, wetlands and culinary salt gives it a distinctive identity within the Algarve.